export const randomString = function(len) {
	len = len || 32;
	let $chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678'; /****默认去掉了容易混淆的字符oOLl,9gq,Vv,Uu,I1****/
	let maxPos = $chars.length;
	let pwd = '';
	for (let i = 0; i < len; i++) {
		pwd += $chars.charAt(Math.floor(Math.random() * maxPos));
	}
	return pwd;
}